Eprom controlled digital thermometer

Τίτλος

Eprom controlled digital thermometer

Θέμα

Thermometers

Automatic control

Δημιουργός

Roushias, Tasos

Πηγή

Higher Technical Institute

Το πλήρες κείμενο είναι διαθέσιμο από το Υπουργείο Ενέργειας, Εμπορίου Βιομηχανίας και Τουρισμού

Εκδότης

Library of Cyprus University of Technology

Ημερομηνία

1991

Δικαιώματα

Απαγορεύεται η δημοσίευση ή αναπαραγωγή, ηλεκτρονική ή άλλη χωρίς τη γραπτή συγκατάθεση του δημιουργού και κάτοχου των πνευματικών δικαιωμάτων.

Μορφή

pdf

Γλώσσα

eng

Τύπος

text

Αναγνωριστικό

EED0173

Σύνοψη

Thermometers are used in our everyday life for various applications. These applications are mainly to sense the temperature and give a signal. That signal is used either to control or to give visual information about the environment where the thermometer is used.
The project's requirements, about the thermometer, is to give in a three seven-segment display the temperature of the thermistor in degrees Celsius (oC).
The design is based on a frequency counter. The sensor is a negative temperature coefficient (NTC) thermistor which by the change of temperature its resistance changes (when the temperature increases the resistance decreases).The thermistor is used with a 555 timer IC. When the temperature changes, the output pulses of the 555 IC change in frequency. These pulses are then counted by the 7493 counters and stored in 7495 memory. The output of 7495 is the address of the memory location in the 2716 EPROM. That memory location contains the data of the respective temperature of the thermistor. That data is in binary and is used by the 7447 decoders to drive the seven segment displays.
The thermometer is calibrated to display temperatures from 0.0oC - 49. 9°C in steps of 0. 1°C.
The use of the EPROM is a nice way to display or control the temperature of specific circuits especially if there is a need of accurate results.